Commit b7eede75 authored by Karsten Graul's avatar Karsten Graul Committed by David S. Miller
Browse files

net/smc: fix work request handling 



Wait for pending sends only when smc_switch_conns() found a link to move
the connections to. Do not wait during link freeing, this can lead to
permanent hang situations. And refuse to provide a new tx slot on an
unusable link.

Fixes: c6f02ebe ("net/smc: switch connections to alternate link")
Reviewed-by: default avatarUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6778a6be

net/smc/smc_llc.c

+4 −4
Original line number Diff line number Diff line
@@ -1241,7 +1241,7 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr) 
	smc_llc_send_message(lnk, &qentry->msg); /* response */



	if (smc_link_downing(&lnk_del->state)) {

		smc_switch_conns(lgr, lnk_del, false);

		if (smc_switch_conns(lgr, lnk_del, false))

			smc_wr_tx_wait_no_pending_sends(lnk_del);

	}

	smcr_link_clear(lnk_del, true);
@@ -1316,7 +1316,7 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr) 
		goto out; /* asymmetric link already deleted */



	if (smc_link_downing(&lnk_del->state)) {

		smc_switch_conns(lgr, lnk_del, false);

		if (smc_switch_conns(lgr, lnk_del, false))

			smc_wr_tx_wait_no_pending_sends(lnk_del);

	}

	if (!list_empty(&lgr->list)) {

net/smc/smc_wr.c

+6 −4
Original line number Diff line number Diff line
@@ -169,6 +169,8 @@ void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context) 
static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)

{

	*idx = link->wr_tx_cnt;

	if (!smc_link_usable(link))

		return -ENOLINK;

	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {

		if (!test_and_set_bit(*idx, link->wr_tx_mask))

			return 0;
@@ -560,15 +562,15 @@ void smc_wr_free_link(struct smc_link *lnk) 
{

	struct ib_device *ibdev;



	if (!lnk->smcibdev)

		return;

	ibdev = lnk->smcibdev->ibdev;



	if (smc_wr_tx_wait_no_pending_sends(lnk))

		memset(lnk->wr_tx_mask, 0,

		       BITS_TO_LONGS(SMC_WR_BUF_CNT) *

						sizeof(*lnk->wr_tx_mask));



	if (!lnk->smcibdev)

		return;

	ibdev = lnk->smcibdev->ibdev;



	if (lnk->wr_rx_dma_addr) {

		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,

				    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,

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